To begin skinning, download one of the skins packages already published, for example, TattooSkin Fire.

First you will want to rename the folder, the lua and the toc to your own skin name. Then open the toc and change the title, author and file name to the names appropriate for your project.

Note that your new skin and your graphics will not load unless you entirely restart WoW. WoW reads all addon names, and all file paths to the graphics, when it first loads, and does not refresh the Addon list or the graphics without a full restart of WoW.

Where it says "Register Border", you create the upper layer of your background panels. Where it says "RegisterTransparency", you create the lower layer of your background panels.

"Fire" is again the name which will appear in the configuration menu. I strongly recommend naming your minimap, borders and transparencies with matching names, so a user can easily find them and use them all together.

Again, you will want to edit the file paths. Each skin set is 12 graphics: the left and right half for Healing, DPSing and Tanking, each of which may have 2 layers. If you don't wish to create 12 graphics, you can make the file paths the same, like so: